1. Field of the Invention
The invention relates to novel cardenolide derivatives and their mineral or organic salts, preparation and therapeutic uses.
2. Description of the Prior Art
It is known that numerous natural substances derived from cardiotonic heterosides are used in therapy for the treatment of cardiac insufficiency. The cardiotonic activity of glycoside cardenolides such as digitoxin depends inter alia on the structure of the cardenolide part and the nature of the 3.beta. sugar chain. These natural substances, however, usually have a narrow therapeutic margin and are therefore difficult to use. Consequently it is desirable to prepare compounds having a similar structure and high cardiotonic activity associated with low toxicity. Compounds of this kind can be obtained by grafting a suitable substituent, e.g. an amino radical as described in French Pat. No. 2,181,694, at 3 on the cardenolide part. The amino radical, however, gives basic properties to these compounds.